Antenna



FIG. 1 is a perspective top view of an antenna;

FIG. 2 is a perspective bottom view of the antenna;

FIG. 3 is a first side elevation view of the antenna;

FIG. 4 is a second side elevation view of the antenna;

FIG. 5 is a third side elevation view of the antenna;

FIG. 6 is a fourth side elevation view of the antenna;

FIG. 7 is a top plan view of the antenna; and,

FIG. 8 is a bottom plan view of the antenna.

The broken and dashed lines shown are for environmental purposes only and form no part of the claimed design. 

The ornamental design for an antenna, as shown and described. 